What he basically did was say, "don't ever print anything negative about a billionaire because they can take down your entire business". So now if a billionaire really does do something newsworthy and negative, places like the New York Times might think twice about publishing that story, for fear of the cost of defending a billionaire's lawsuit.
That's why people dislike him (other than his Trump support, although to be fair I haven't heard anything about him supporting Trump anymore).